Economic Burden of Adverse Events Associated with Immunotherapy and Targeted Therapy for Metastatic Melanoma in the Elderly

BACKGROUND: Immunotherapies and targeted therapies have drastically improved survival in metastatic melanoma, but they can cause a range of adverse events (AEs). Understanding the costs of these events would facilitate an accurate comparison of melanoma treatments. OBJECTIVE: To compare the costs and frequency of AEs associated with immunotherapy and with targeted therapy in elderly patients with metastatic melanoma. METHODS: We conducted a retrospective cohort study using Medicare claims data from 2011 to 2014. Patients included had to have >= 1 diagnoses of metastatic melanoma and >= 1 claims for an immunotherapy or targeted therapy. We compared the 30-day expenditures of patients with and without each AE using a generalized linear model to determine the incremental cost per AE in patients who received immunotherapy or targeted therapy. The baseline demographic and clinical differences were adjusted for using propensity score with inverse probability of treatment. We also compared the mean costs of AEs associated with immunotherapy and targeted therapy. RESULTS: A total of 844 patients were included in the study (mean age, 75 years; standard deviation, 14 years). The mean baseline Charlson Comorbidity Index score was 8.4, and 65% of the patients were male. The mean cost for AEs was highest for respiratory events (ie, $24,150). Gastrointestinal, respiratory, and hematologic AEs were more common in patients who received immunotherapy, whereas general and administration-site AEs and other AEs (eg, fatigue, infections, muscular weakness) were more frequent in patients who received targeted therapy. AE-related costs with immunotherapy were highest for gastrointestinal, respiratory, and pain-related AEs; AEs with targeted therapy were highest for cardiovascular and general and administration-site events. CONCLUSION: These findings suggest that incremental costs associated with treatment-related AEs among elderly patients with metastatic melanoma were substantial, but the risks for and costs of the various types of AEs differed by therapy. Understanding the risks for and costs of AEs associated with the various therapeutic options can inform treatment decision-making in elderly patients with metastatic melanoma.